SetDirectory["C:\\drorbn\\AcademicPensieve\\Projects\\Quadraticity"]

img=Import["Oregon-8.png"]

Dimensions[im=Normal[img[[1]]]]

GraphicsGrid[Partition[
Table[
bs=2^(8-k);
ps = Graphics[
Raster[Reverse[Total[Partition[im, {bs,bs}], {3,4}]/bs^2/255.]
],
ImageSize -> 256, ImagePadding -> None, PlotRangePadding -> None
];
Export["Oregon-"<>ToString[k]<>".png", ps];
ps,
{k,0,7}
],2]]